McKenna's Pharmacology for Nursing, 2e

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Diuretic agents

Learning objectives Upon completion of this chapter, you should be able to: 1. Define the term diuretic and list the five classes of diuretics.

2. Describe the therapeutic actions, indications, pharmacokinetics, contraindications and cautions, most common adverse reactions, and important drug–drug interactions associated with the various classes of diuretic drugs. 3. Discuss the use of diuretic agents across the lifespan. 4. Compare and contrast the prototype drugs of each class of diuretic drugs with other agents in their class. 5. Outline the care considerations, including important teaching points, for people receiving diuretic agents.

Test your current knowledge of diuretic agents with a PrepU Practice Quiz!

Glossary of key terms alkalosis: state of not having enough acid to maintain normal homeostatic processes; seen with loop diuretics, which cause loss of bicarbonate in the urine fluid rebound: reflex reaction of the body to the loss of fluid or sodium; the hypothalamus causes the release of antidiuretic hormone, which promotes water retention, and stress related to fluid loss combines with decreased blood flow to the kidneys to activate the renin–angiotensin–aldosterone system, leading to further water and sodium retention high-ceiling diuretics: powerful diuretics that work in the loop of Henle to inhibit the reabsorption of sodium and chloride, leading to a sodium-rich diuresis hyperaldosteronism: excessive output of aldosterone from the adrenal gland, leading to increased sodium and water retention and loss of potassium hypokalaemia: low potassium in the blood, which often occurs after diuretic use; characterised by weakness, muscle cramps, trembling, nausea, vomiting, diarrhoea and cardiac arrhythmias oedema: movement of fluid into the interstitial spaces; occurs when the balance between osmotic pull (from plasma proteins) and hydrostatic push (from blood pressure) is disturbed osmotic pull: drawing force of large molecules on water, pulling it into a tubule or capillary; essential for maintaining normal fluid balance within the body; used to draw out excess fluid into the vascular system or the renal tubule saluretic effect: relating to or causing excretion of salt

DIURETICS Thiazide diuretics and thiazide-like diuretics Thiazide diuretics hydrochlorothiazide Thiazide-like diuretics chlorthalidone indapamide

Loop diuretics bumetanide ethacrynic acid frusemide Carbonic anhydrase inhibitors

Potassium-sparing diuretics amiloride eplerenone spironolactone triamterene

Osmotic diuretics glucose mannitol

acetazolamide brinzolamide